The present invention relates to a nozzle for direct metal deposition and other laser welding applications. In particular, the present invention relates to a powder feed nozzle for use for direct metal deposition and other laser welding applications.
Laser welding applications use high powered lasers or other high energy sources to melt deposited material for welding. Laser welding is used to fabricate components by a direct metal deposition technique to form various shapes and forms. The deposited structure may be machined to a desired finish to complete the fabrication process.
Powder is dispersed from feed nozzles to a molten puddle or pool formed by the laser. Catchment is a term which refers to the amount of powder deposited to the molten pool relative to the amount of powder discharged or dispersed from the nozzle. If the dispersement profile of powder discharged from the nozzle is greater than the area of the molten pool or puddle, then catchment is poor since powder is dispersed to areas surrounding the molten pool in addition to the molten pool. Powder that is deposited outside of the molten pool can have certain deleterious effect on the metallurgical qualities and performance of the resulting structure as well as increased costs.
During a forming operation, molten and other material from the workpiece can spatter to the nozzle which can clog the nozzle. The closer the nozzle is to the workpiece the greater propensity that spatter will clog the nozzle. Residue spattered to the nozzle can alter the profile of powder dispersed from the nozzle or completely clog the nozzle. Reflected laser beams from the melt puddle can also sinter powder or melt the nozzle tip. The present invention addresses these and other problems.
The present invention relates to a powder feed nozzle for laser welding applications including a multiple outlet nozzle tip for focusing a discharged powder stream. The multiple outlet nozzle tip disperses multiple outlet streams and includes a powder discharge outlet and at least one focus gas discharge outlet, radially spaced from the powder discharge outlet, for dispersing a powder stream and a gas stream. Powder flows from a powder source through a powder channel to the powder discharge outlet for dispersement. Focus gas flows through a focus gas channel angled relative to the powder channel to discharge a focus gas stream.